Rare Unusual Male Bear Gulch Falcatus Shark Fossil

Falcatus falcatus

Class Chondrichthyes, Subclass Elasmobranchii, Order Symmoriida
Family Falcatidae (also seen as: Cladodontida, Stethacanthidae)

Geological Time: Mississippian (~320 m.y.a.)

Size: Fish fossil is 100 mm long

Fossil Site: Heath Shale Formation, Bear Gulch Limestone, Fergus County, Montana

Falcatus falcatus Shark FossilDescription: The Bear Gulch Limestone is a deposit of some 70 square km in extent and 30 m in depth that has been a source of one of the most diverse assemblages of fossil fish with some 110 species having been described over the past 30 years. Most were new to science, and provided a unique view of the marine environment of Mississippian times. Fine preservation of both fish and invertebrates is a hallmark of these Falcatusdeposits, presumably due to an anoxic depositional environment. This specimen is an unusual shark that possesses a strong sexual dimorphism. The spine is only found on the male, and is thought to have been involved in mating. Indeed, a specimen is known in which the female was preserved above the male with the dorsal spine grasped in her mouth in what has been interpreted as a mating ritual. This specimen shows the spine in life position with the vertebral column curved over the head. Note the fine teeth dispersed around the lower side of the head. This is the FIRST and ONLY near-complete example I have had to offer. See my other offerings for a fine spine of a somewhat larger specimen.

click to enlarge fossil pictures


l Paleontology & Fossils l Paleobiology and Geologic Timeline l
l Fossil Amber l Ammonite Fossils l Dinosaur and Reptile Fossils l Fossil Kits l
l Crinoids and Echinoderms l Fish Fossils l Fossil Dealers l Insect Fossils l Invertebrate Fossils l
l Plant Fossils l Stromatolites l Trace & Ichnofossils l Trilobite Fossils l Vertebrate Fossils l